It is known that such a fuel pump comprises a bell, an electric motor, and a suction mechanism. For reasons of simplification, it is assumed below that the motor incorporates the suction mechanism.
The bell, which is designed to be contact with the fuel, lies inside the tank. It has a fuel suction port, and a fuel delivery port. For safety reasons, the electric motor lies outside the tank, being fastened directly to the bell so as to be carried by the bell through the panel of the tank. Sealing between the bell and the tank is provided by means of an O-ring. The bell is fastened directly to the panel of the tank by means of a fastener screw having its head bearing against an outside face of the panel and having its shank fastened to the bell by means of a nut.
That arrangement presents drawbacks.
Thus, sealing between the bell and the panel is sensitive to the quality of the panel, and in particular to its surface state or indeed to any shape defect, given the size of the pump. Unfortunately, it is clearly essential to ensure good sealing at the interface between the pump and the panel in order to ensure that no kerosene leaks out from the tank.
Pump bells are also sensitive to deformation of panels to such an extent that they sometimes break as a result of the forces generated by such deformation, in particular because the screws that are used for fastening the bell pass through the panel. Consequently, in order to guarantee that the pump is reliable, it is desirable to make its fastening insensitive to any structural deformation.
Solutions have been proposed to mitigate those problems, but they are not always satisfactory.
Thus, proposals have been made to lap the surface of the panel on which the bell comes to bear so as to guarantee the surface state and the shape of its bearing face. Proposals have also been made to reinforce the structure. Nevertheless, no solution has been proposed that avoids the bell breaking.
Those problems are encountered when the panel of the tank is made of metal. However, when it is made of composite material, those problems are accompanied by the problem whereby the temperature of the pump rises in the event of a breakdown. Heat is then transmitted to the panel, and that modifies the characteristics of the composite material.